Cell population kinetics in the epithelium of the colon of the male rat

Abstract

Some kinetic parameters in the colonic mucosa of normal Wistar rats were studied. Preliminary observations showed considerable morphological differences in the mucosa from site to site along the length of the colon. In particular the height of the crypts (measured in cells) was variable. Labeling index studies demonstrated dramatic variations in the distribution of labeling along the length of the crypts from site to site in the bowel. A single site in the descending colon was selected for more detailed study using a stathmokinetic agent, vincristine, and the continuous labeling technique with 3H thymidine. There apparently exists at the base of the crypt a subpopulation of cells cycling more slowly than the cells in the rest of the proliferative compartment. Growth fraction appears to fall with rising cell positions within the crypt.